<html>
<head>
<meta charset="utf-8">
<style type="text/css">
ul{ padding: 0; margin: 0; list-style-type: none;}
.menu{width: 940px; height: 35px;}
a{ text-decoration: none;color: #fff;}
.menu>ul>li{ position: relative; width: 150px; height: 35px; float: left;}
.menu>ul>li>a{ line-height: 35px; float: left; height: 35px; text-align: center;background:#c00; width: 150px; font-size: 14px; letter-spacing: 4px; font-weight: bold;}
.menu>ul>li>a:hover{ background: #036; color: #ff0;}
.menu>ul>li>ul{ position: absolute;width: 150px; height:auto; left: 0; top: 35px; background: #eef; display: none;}
.menu>ul>li>ul>li{height:30px;line-height:30px;}
.menu>ul>li>ul a{display: block;  height: 30px; font-size: 12px;line-height:30px; text-align: center; color: #036; border-bottom: 3px solid #fff; letter-spacing: 4px; overflow: hidden;}
.menu>ul>li>ul a:hover{background: #c00; color: #ff0;}
</style>

</head>
<body>
<div class="menu">
<ul>
<li><a href="#" >首页</a></li>

<li><a href="#">电脑版</a>
	<ul>
		
		<li><a href="#">一级页面</a></li>
		<li><a href="#">二级页面</a></li>
		<li><a href="#">三级页面</a></li>
	</ul>
</li>
<li><a href="#" >手机版</a>
	<ul>
		<li><a href="#">一级页面</a></li>
		<li><a href="#">二级页面</a></li>
		<li><a href="#">三级页面</a></li>
	</ul>
</li>
<li><a href="#">网页元素</a>
	<ul>
		<li><a href="#">基本网页元素</a></li>
		<li><a href="#">JS网页元素</a></li>
		<li><a href="#">jQuey网页元素</a></li>
		<li><a href="#">CSS3网页元素</a></li>
	</ul>
</li>
</ul>
</div>
<script type="text/javascript" src="jquery.min.js"></script>
<script type="text/javascript">
$(function () {
    $(".header").mouseover(function (){  
            $(".content").show();  
        }).mouseout(function (){  
            $(".content").hide();  
        });  
		
});
</script>
</body>
</html>
